Giantkiller,
Please read the other posting that I just made to Mags and Groundloop. Your pulses are quite short and microwave transmission line effects may be coming into play. The voltage wavefront travels along the wire and then gets reflected back when it reaches the open-circuited end of the coil. Same as I said in the other posting, it may be more appropriate to call it a length of wire that acts like a transmission line than a coil when the pulses get very very short in duration.
So what you might really be looking at is voltage wavefronts bouncing back and forth along the length of wire that forms the coil, and any inductance effects are secondary or non-existent. You can see in some of your traces it looks roughly like two superimposed waveforms that are interfering with each other. If you tried a similar coil but with a longer total length of wire, you might start to recognize that the superimposed wavefronts are changing in their relative timing because of the longer transmission line length before the reflections takes place.
The bottom line Giantkiller, is that you are observing exactly what is supposed to be happening, nothing more and nothing less. An analogy is the whole pulse motor "speed up under load" or "delayed Lenz effect" business. In those cases nobody has achieved anything or has done something special, even though they think they have.
MileHigh
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